1. Field of the Invention
This invention relates to an IC card having a control unit and a storage unit provided therein, for receiving various commands from an external device so as to execute various processes in accordance with the received various commands.
2. Description of the Related Art
An IC card has recently been used in various fields. The IC card comprises a contact unit disposed on the surface of the IC card and electrically connected to an external device so as to effect the transfer of signals and data between the external device and the contact unit, and a semiconductor device disposed inside the IC card. This type of semiconductor device is normally comprised of a control unit including a microprocessor, etc., a Read Only Memory (ROM) for storing control programs therein, an Electrically Erasable Programmable Read Only Memory (EEPROM), etc. The EEPROM stores transaction data and the like used for the IC card therein.
This type of IC card has been employed in banking facilities such as a bank, etc. Due to the nature of banking transactions, the IC card employed in banking facilities requires high security.
Such an IC card has been disclosed in, for example, Japanese Patent Application Laid-Open Publication No. 2-89169 laid open to public inspection on Mar. 29, 1990.